Movement Kinematics Research Articles

Tutorials + PhET: a simple and efficient active-learning approach for the teaching of kinematics of circular motion in a technically-oriented high school

A quasi-experimental group comparison experiment was conducted to improve the conceptual learning of rotational kinematics by 11th grade students of a technically-oriented high school in Argentina. The experimental instruction complemented the original Tutorials in Introductory Physics activities with the PhET simulation Ladybug Revolution. Conceptual learning was determined with pre and post instruction application of the multiple-choice test Rotational Kinematics Inventory (RKI). This procedure allowed for the determination of a large difference in normalized learning gain between the experimental (g = 0.48) and control (g = 0.17) groups. It is also shown that the final conceptual knowledge of the experimental group is clearly higher than that of the students and teachers samples used in developing the RKI. An analysis of the institutional evaluation showed that this important difference in conceptual learning between the two groups did not affect the problem-solving performance of the experimental group. These results indicate the convenience of affecting part of the problem-solving classroom time in the proposed experimental instruction. A few recommendations to improve the experimental teaching approach are given.

The influence of body segment estimation methods on body segment inertia parameters and joint moments in javelin throwing

Calculated intersegmental moments are commonly used in analyzing throwing movements. The inverse dynamics (ID) results can vary due to the chosen set of body segment inertia parameters (BSIP). A multitude of methods to determine BSIP sets are available. The purpose of this study was to clarify the influence of different estimation methods on the BSIPs and the respective impact on the ID results in javelin throwing. Movement kinematics were recorded for ten male javelin throwers. Six different methods were used to estimate BSIP sets for the upper extremities of each thrower. Subsequently, ID results were obtained for each thrower and BSIP set. Results show variations between 8% and 120% between the BSIP sets, and maximum intersegmental moments varied between 6% and 21%, respectively. Joint-specific variations of intersegmental moments were observed as well as movement-specific variations within a joint related to the different BSIP sets. Furthermore, the influence of BSIP sets appears to be subject-specific as well, with observed variations between 9% and 18% – some athletes are better represented by the chosen methods than others. Hence, our study results suggest that the method to determine BSIP sets needs to be carefully chosen for calculating joint kinetics in throwing movements.

Evaluation of the physiological benefits of a passive back-support exoskeleton during lifting and working in forward leaning postures

Musculoskeletal disorders affecting the back are highly prevalent in fields of occupation involving repetitive lifting and working in forward leaning postures. Back-support exoskeletons are developed to relieve workers in physically demanding occupations. This study investigates the physiological effects of a lightweight exoskeleton which provides support through textile springs worn on the back. We hypothesized that wearing such a passive back-support exoskeleton reduces muscle activity of the back and hip muscles, while not influencing abdominal muscle activity and movement kinematics during typical occupational tasks.We collected electromyography data from the main back and hip muscles as well as whole body kinematics data via optical motion tracking during a set of relevant weight lifting tasks corresponding to typical work conditions. In our sample of 30 healthy volunteers, wearing the exoskeleton significantly reduced muscle activity, with reductions up to 25.59% during forward leaning and 20.52% during lifting in the main back and hip muscles (Erector Spinae at thoracic and lumbar level and Quadratus Lumborum). Simultaneously, no changes in knee and hip range of motion were observed. The stretch of the textile springs correlated with the body mass index and chest circumference of the wearer, and depended on posture, but not on the lifted load.The LiftSuit exoskeleton relieved back and hip muscles during typically straining occupational tasks, while biomechanical parameters were preserved. This suggests that passive lift-support exoskeletons can be safely used to relieve workers during lifting and forward leaning tasks.

Evaluation of the Malalignment Varus - Valgus in Total Knee Arthroplasty Designed for Deep Knee Flexion Using Knee Kinematic Motion Simulator

Revision total knee arthroplasties cause performed aseptic loosening, instability, and polyethylene wear. Separation or removal of the femoral component has been observed and this has the potential to severely damage the polyethylene component. In most cases 90% of the patients examined experienced significant medial or lateral condylar lift at some stage during the gait cycle. Using the MRI, a normal knee has maximum lateral lift is approx. 6.7 mm and maximum medial lift is approx. 2.1 mm, when a varus strees applied at a 90° knee flexion. Elevation of the lateral condyle due to valgus malalignment will distribute more contact force on the medial condyle. In this study, a polyethylene component of a posterior-stabilized right knee joint implant was developed to facilitate a high range of motion (ROM). Malalignment valgus was observed with the axes of knee motion joint implants were varied from 0°, 2°, 3° to 5 and knee bend measurements at 30°, 60°, 90°, 120°, and 150° of knee flexion. Using the knee kinematic motion simulator, the modified polyethylene component resulted in 0° malalignment there is no gap of the femoral component with the polyethylene component, from 30° to 150° of knee flexion. At 2° malalignment, the femoral component was raised by 0.5 mm at a 90° to 150° knee flexion and increased with increasing knee flexion. Maximum gap occurs at 5° malalignment in the amount of 5 mm at 150° of knee flexion. The aim of this study was therefore to evaluation malalignment valgus of the flexed knee using knee kinematic motion simulator, with reference to the tibiofemoral flexion gap. The result that the modified design is expected in an narrow down gap between femoral and polyethylene component used knee kinematic motion simulator, this accommodate deep knee flexion movement in daily activities and reduce the possibility of subluxation and dislocation at the polyethylene component during deep knee flexion. A wide gap between the femoral component and the polyethylene component and a significant amount of contact force in the medial condyle region might be the explanation for polyethylene component damage. It is expected that potential medial or lateral condylar lift at some stage during the gait cycle can be reduced.

Inhibition of knee joint sensory afferents alters covariation across strides between quadriceps muscles during locomotion.

Sport-related injuries to articular structures often alter the sensory information conveyed by joint structures to the nervous system. However, the role of joint sensory afferents in motor control is still unclear. Here, we evaluate the role of knee joint sensory afferents in the control of quadriceps muscles, hypothesizing that such sensory information modulates control strategies that limit patellofemoreal joint loading. We compared locomotor kinematics and muscle activity before and after inhibition of knee sensory afferents by injection of lidocaine into the knee capsule of rats. We evaluated whether this inhibition reduced the strength of correlation between the activity of vastus medialis (VM) and vastus lateralis (VL) both across strides and within each stride, coordination patterns that limit net mediolateral patellofemoral forces. We also evaluated whether this inhibition altered correlations among the other quadriceps muscle activity, the time-profiles of individual EMG envelopes, or movement kinematics. Neither the EMG envelopes nor limb kinematics was affected by the inhibition of knee sensory afferents. This perturbation also did not affect the correlations between VM and VL, suggesting that the regulation of patellofemoral joint loading is mediated by different mechanisms. However, inhibition of knee sensory afferents caused a significant reduction in the correlation between vastus intermedius (VI) and both VM and VL across, but not within, strides. Knee joint sensory afferents may therefore modulate the coordination between the vasti muscles but only at coarse time scales. Injuries compromising joint afferents might result in altered muscle coordination, potentially leading to persistent internal joint stresses and strains.NEW & NOTEWORTHY Sensory afferents originating from knee joint receptors provide the nervous system with information about the internal state of the joint. In this study, we show that these sensory signals are used to modulate the covariations among the activity of a subset of vasti muscles across strides of locomotion. Sport-related injuries that damage joint receptors may therefore compromise these mechanisms of muscle coordination, potentially leading to persistent internal joint stresses and strains.

Physiological Demands of a Self-Paced Firefighter Air-Management Course and Determination of Work Efficiency

To assess the physiological demands of an AMC and examine differences across BMI categories. A secondary aim was to develop an equation to assess work efficiency in firefighters. Fifty-seven firefighters (Women, n = 4; age: 37.2 ± 8.4 yr.; height: 182.0 ± 6.9 cm; body mass: 90.8 ± 13.1 kg; BMI: 27.8 ± 3.6 kg·m-2) completed an AMC per routine evaluation while wearing a department issued self-contained breathing apparatus and full protective gear. Course completion time, starting pounds per square inch (PSI) on the air cylinder, changes in PSI, and distance traveled were recorded. All firefighters were equipped with a wearable sensor integrated with a triaxial accelerometer and telemetry to assess movement kinematics, heart rate, energy expenditure, and training impulse. The AMC consisted of an initial section involving a hose line advance, rescue (body drag), stair climb, ladder raise, and forcible entry. This section was followed by a repeating loop, which consisted of a stair climb, search, hoist, and recovery walk. Firefighters repeated the course loop until the self-contained breathing apparatus air supply pressure reached 200 PSI, at which time they were instructed to lay down until the PSI reached zero. Average completion time was 22.8 ± 1.4 min, with a mean distance of 1.4 ± 0.3 km and an average velocity of 2.4 ± 1.2 m·s-1. Throughout the AMC, the mean heart rate was 158.7 ± 11.5 bpm equating to 86.8 ± 6.3% of the age-predicted max heart rate and a training impulse of 55 ± 3 AU. Mean energy expenditure was 464 ± 86 kcals and work efficiency was 49.8 ± 14.9 km·PSI-1·s. Regression analysis determined that fat-free mass index (R2 = 0.315; β = -5.069), body fat percentage (R2 = 0.139; β = -0.853), fat-free mass (R2 = 0.176; β = -0.744), weight (R2 = 0.329; β = -0.681), and age (R2 = 0.096; β = -0.571) were significant predictors of work efficiency. The AMC is a highly aerobic task with near-maximal heart rates reached throughout the course. Smaller and leaner individuals achieved a higher degree of work efficiency during the AMC.

An Explainable Spatial-Temporal Graphical Convolutional Network to Score Freezing of Gait in Parkinsonian Patients.

Freezing of gait (FOG) is a poorly understood heterogeneous gait disorder seen in patients with parkinsonism which contributes to significant morbidity and social isolation. FOG is currently measured with scales that are typically performed by movement disorders specialists (i.e., MDS-UPDRS), or through patient completed questionnaires (N-FOG-Q) both of which are inadequate in addressing the heterogeneous nature of the disorder and are unsuitable for use in clinical trials The purpose of this study was to devise a method to measure FOG objectively, hence improving our ability to identify it and accurately evaluate new therapies. A major innovation of our study is that it is the first study of its kind that uses the largest sample size (>30 h, N = 57) in order to apply explainable, multi-task deep learning models for quantifying FOG over the course of the medication cycle and at varying levels of parkinsonism severity. We trained interpretable deep learning models with multi-task learning to simultaneously score FOG (cross-validated F1 score 97.6%), identify medication state (OFF vs. ON levodopa; cross-validated F1 score 96.8%), and measure total PD severity (MDS-UPDRS-III score prediction error ≤ 2.7 points) using kinematic data of a well-characterized sample of N = 57 patients during levodopa challenge tests. The proposed model was able to explain how kinematic movements are associated with each FOG severity level that were highly consistent with the features, in which movement disorders specialists are trained to identify as characteristics of freezing. Overall, we demonstrate that deep learning models' capability to capture complex movement patterns in kinematic data can automatically and objectively score FOG with high accuracy. These models have the potential to discover novel kinematic biomarkers for FOG that can be used for hypothesis generation and potentially as clinical trial outcome measures.

A sampling and learning framework to prove motion planning infeasibility

We present a learning-based approach to prove infeasibility of kinematic motion planning problems. Sampling-based motion planners are effective in high-dimensional spaces but are only probabilistically complete. Consequently, these planners cannot provide a definite answer if no plan exists, which is important for high-level scenarios, such as task-motion planning. We apply data generated during multi-directional sampling-based planning (such as PRM) to a machine learning approach to construct an infeasibility proof. An infeasibility proof is a closed manifold in the obstacle region of the configuration space that separates the start and goal into disconnected components of the free configuration space. We train the manifold using common machine learning techniques and then triangulate the manifold into a polytope to prove containment in the obstacle region. Under assumptions about the hyper-parameters and robustness of configuration space optimization, the output is either an infeasibility proof or a motion plan in the limit. We demonstrate proof construction for up to 4-DOF configuration spaces. A large part of the algorithm is parallelizable, which offers potential to address higher dimensional configuration spaces.

Submarine control system using sliding mode controller with optimization algorithm

<span>The purpose of this paper is to design and implement the pitch and depth control system of an autonomous underwater vehicles (AUV). This control system will determine the best pitch angle as well as the depth automatically when there are changes in speed, weight, etc. In this paper, the kinematic and dynamic equations of motion for the AUV are derived to obtain the pitch angle and depth transfer functions. The control strategies applied here, are firstly, the sliding mode controller (SMC) driven by particle swarm optimization (PSO) algorithm. Secondly, the proportional integral derivative controller (PID) tuned by PSO algorithm as a standard controller. The PSO algorithm is used as an efficient algorithm to search for the optimal controllers’ parameters and hence improving the performance of the system. The findings show that the designed sliding mode control (SMC) could improve the stability and performance and provides more realistic behavior for the AUV compared to other classical controllers and according to pitch and the depth changes.</span>

Lateral Vehicle Trajectory Planning Using a Model Predictive Control Scheme for an Automated Perpendicular Parking System

This article proposes a lateral vehicle trajectory planning and control algorithm using a model predictive control (MPC) scheme for an automated perpendicular parking system. Previous work showed that approximated clothoid-based local path planning using a virtual towing distance provides low computational time and the stability of lateral vehicle motion in a parking system. However, this approach cannot function in certain parking situations and may cause undesirable steering maneuvers due to state-dependent planning. We present a new approximated clothoid path based on lateral vehicle kinematics to cope with these problems. Using the proposed kinematic model, we formulate an MPC problem for path planning. Then, the proposed lateral vehicle trajectory planning becomes an MPC problem under constraints. Besides, we show that lateral vehicle motion for vertical parking can be implemented using simple kinematic lateral motion control. Experimental results show that the vehicle with the proposed method moves smoothly and completes the given parking mission under constraints, even under tight parking space conditions.

Opportunities for Improving Motor Assessment and Rehabilitation After Stroke by Leveraging Video-Based Pose Estimation

Stroke is a leading cause of long-term disability in adults in the United States. As the healthcare system moves further into an era of digital medicine and remote monitoring, technology continues to play an increasingly important role in post-stroke care. In this Analysis and Perspective article, opportunities for using human pose estimation-an emerging technology that uses artificial intelligence to track human movement kinematics from simple videos recorded using household devices (e.g., smartphones, tablets)-to improve motor assessment and rehabilitation after stroke are discussed. The focus is on the potential of two key applications: (1) improving access to quantitative, objective motor assessment and (2) advancing telerehabilitation for persons post-stroke.

Limb loading enhances skill transfer between augmented and physical reality tasks during limb loss rehabilitation

BackgroundVirtual and augmented reality (AR) have become popular modalities for training myoelectric prosthesis control with upper-limb amputees. While some systems have shown moderate success, it is unclear how well the complex motor skills learned in an AR simulation transfer to completing the same tasks in physical reality. Limb loading is a possible dimension of motor skill execution that is absent in current AR solutions that may help to increase skill transfer between the virtual and physical domains.MethodsWe implemented an immersive AR environment where individuals could operate a myoelectric virtual prosthesis to accomplish a variety of object relocation manipulations. Intact limb participants were separated into three groups, the load control (CGLD; N=4), the AR control (CGAR; N=4), and the experimental group (EG; N=4). Both the CGAR and EG completed a 5-session prosthesis training protocol in AR while the CGLD performed simple muscle training. The EG attempted manipulations in AR while undergoing limb loading. The CGAR attempted the same manipulations without loading. All participants performed the same manipulations in physical reality while operating a real prosthesis pre- and post-training. The main outcome measure was the change in the number of manipulations completed during the physical reality assessments (i.e. completion rate). Secondary outcomes included movement kinematics and visuomotor behavior.ResultsThe EG experienced a greater increase in completion rate post-training than both the CGAR and CGLD. This performance increase was accompanied by a shorter motor learning phase, the EG’s performance saturating in less sessions of AR training than the CGAR.ConclusionThe results demonstrated that limb loading plays an important role in transferring complex motor skills learned in virtual spaces to their physical reality analogs. While participants who did not receive limb loading were able to receive some functional benefit from AR training, participants who received the loading experienced a greater positive change in motor performance with their performance saturating in fewer training sessions.

Absent epiglottic inversion as seen on flexible endoscopic evaluations of swallowing (FEES) is associated with a gestalt reduction in swallowing mechanics

PurposeEpiglottic inversion, which provides one layer of the requisite protection of the airway during swallowing, is dependent on a number of biomechanical forces. The aim of this study was to examine the association between swallowing mechanics, as visualized during a Modified Barium Swallow (MBS) exam, and the rating of epiglottic inversion as seen on Flexible Endoscopic Evaluation of Swallowing (FEES). MethodsThis study analyzed twenty-five adult outpatients referred for a simultaneous FEES/MBS exams. Each participant swallowed a 5 mL thin liquid bolus, which was the bolus size analyzed for this study's question. Epiglottic inversion, as seen on FEES, was rated by three independent raters. Additionally, twelve swallowing landmarks tracked the shape change of each participant's swallow on the MBS video using a MatLab-specific tracking tool. Analyses were run to determine mean differences in swallowing shape change between the swallows across 3 groups: complete, reduced, and absent epiglottic inversion, as seen on FEES. Using a Computerized Analysis of Swallowing Mechanics (CASM), canonical variate analyses and discriminant function testing were carried out. Other swallowing mechanics were also analyzed for kinematic movements to isolate the function of the hyoid and larynx. A two-sample t-test was conducted to compare mean hyolaryngeal movement between complete and incomplete epiglottic inversion groups. ResultsOverall swallowing shape changes were statistically significantly different between the absent, reduced, and complete epiglottic inversion groups on FEES. Canonical variate analyses revealed a significant overall effect of shape change between the groups (eigenvalue = 2.46, p < 0.0001). However, no statistically significant differences were found on hyoid excursion (p = 0.37) and laryngeal elevation (p = 0.06) kinematic measurements between patients with complete and incomplete epiglottic inversion on FEES. ConclusionEpiglottic inversion on FEES is a valuable rating that infers reduced range of motion of structures that cannot be seen on FEES. This small sample of patients suggests that FEES ratings of absent epiglottic inversion may represent gestalt reduction in swallowing mechanics.

Kinematics analysis, motion planning and control of the continuum manipulator in minimally invasive surgery

Due to its unique dexterity, flexibility, and safety, continuum manipulator is more suitable for the detection, diagnosis, and maintenance in complex, narrow, and unstructured constrained environment. This paper presented a new cable-driven flexible endoscope robot for diagnosis and treatment, and its kinematics model, motion planning and control performance were systematically studied. First of all, the kinematics model of the proposed continuum manipulator was established by D-H method, and the workspace was analyzed based on the improved Monte Carlo method. In order to make the multi-segment continuum robot safety and quickly intervene into the target area, a motion planning method was proposed by using the ridge method under the constraints of the navigation path. In other words, the minimum distance between the beginning point, middle point and distal point of the robot and the theoretical trajectory points was taken as the optimization function, the configuration parameters of each bending segment were solved by inverse recursion to control the robot move along the pre-given navigation path. Then, the motion planning simulations of the plane path and spatial path were carried out to verify the proposed motion planning method. Finally, the experimental prototype of the proposed endoscopic robot was set up to verify the feasibility of the proposed continuum structure and the correctness of the established model, which can be used as a feedback control and navigation reference.

Hierarchical approach for fusion of electroencephalography and electromyography for predicting finger movements and kinematics using deep learning

The brain is a unique organ that performs multiple processes simultaneously, such as sensory, motor, and cognitive function. However, several neurological diseases (ataxia, dystonia, Huntington’s disease) or trauma affect the limb movement and there is no cure. Although brain-computer interfaces (BCIs) have been recently used to improve the quality of life for people with severe motor disabilities, anthropomorphic control of a prosthetic hand in upper limb rehabilitation still remains an unachieved goal. To this purpose, a hierarchical integration of neural commands to fingers was applied for execution of human hand grasping with better precision. For finger movement prediction and kinematics estimation, a neuromuscular approach was employed to establish a hierarchical synergy between electroencephalography (EEG) and electromyography (EMG). EEG, EMG and metacarpophalangeal (MCP) joint kinematics were acquired during five finger flexion movements of the human hand. EMG for five finger movements and kinematics were estimated from EEG using linear regression. A Long Short-Term Memory network (LSTM) and a random forest regressor were adjoined hierarchically for prediction of finger movements and estimation of finger kinematics from the estimated EMG. The results showed an average accuracy of 84.25 ± 0.61 % in predicting finger movements and an average minimum error of 0.318 ± 0.011 in terms of root mean squared error (RMSE) in predicting finger kinematics from EEG across six subjects and five fingers. These findings suggest the implementation of a hierarchical approach to develop anthropomorphic control for upper limb prostheses.

Robotic biomechanical evaluation of six different reverse shoulder implants

BackgroundThe reverse total shoulder arthroplasty is a popular surgical treatment for a degenerative shoulder with a nonfunctional rotator cuff. Currently, more than 36 different brands with small different features are available. This creates choice stress among many surgeons, who no longer know which parameters and surgical factors are important to optimize the placement of the implant. PurposeThe first purpose of this pilot study was to compare the passive range of motion (ROM) of 6 different implant designs implanted following the manufacturer’s guidelines. The second goal was to identify the impingements after implantation which determines the maximal ROM. The last goal of the study was to link the different parameters of an implant with the ROM. MethodsSix implant systems were implanted on identical sawbones. The procedure was repeated 3 times on a different sawbone to objectify the surgical repeatability of the procedures. A Stäubli TX-90 robot was used to perform and control the humerus' kinematic movement. An optical tracking system was used to perform the system's calibrations, track the humerus and scapula in space, and compute the center of rotation. ResultsThere was a wide ROM in the scapular plane (44.8°-105.5°) while the minimal elevation (adduction) varied between −4.8° and 35.6°. The rotational movements were limited by contact of the superior humeral polyethylene inlay and the inferior scapular neck. The adduction in the coronal and scapular plane was limited by inferior scapular impingement, whereas the maximal abduction was limited either by bony contact between the humerus and acromion or by contact between the humeral polyethylene inlay and the superior glenoid cavity. A bigger radius of the glenosphere resulted in a larger passive humeroscapular ROM (P < .001). A larger Neck-Shaft-Angle results in a better abduction (P < .001) but compromised adduction (P < .001). The localization of the center of rotation has a significant impact on the ROM. The medialized designs have larger abduction and rotational angles (P < .001). ConclusionThere is a wide variation in the measured glenohumeral ROM between the 6 frequently implanted prostheses. The most important factor to optimize the impingement-free ROM in all types of prostheses is the creation of the prosthetic overhang of the glenosphere to the bone. Too much lateralization of the center of the glenosphere with or without lateralization of the humeral stem can create a subacromial and/or subcoracoidal impingement.

Criterion validity of neural networks to assess lower limb motion during cycling

ABSTRACT The use of marker-less methods to automatically obtain kinematics of movement is expanding but validity to high-velocity tasks such as cycling with the presence of the bicycle on the field of view is needed when standard video footage is obtained. The purpose of this study was to assess if pre-trained neural networks are valid for calculations of lower limb joint kinematics during cycling. Motion of twenty-six cyclists pedalling on a cycle trainer was captured by a video camera capturing frames from the sagittal plane whilst reflective markers were attached to their lower limb. The marker-tracking method was compared to two established deep learning-based approaches (Microsoft Research Asia-MSRA and OpenPose) to estimate hip, knee and ankle joint angles. Poor to moderate agreement was found for both methods, with OpenPose differing from the criterion by 4–8° for the hip and knee joints. Larger errors were observed for the ankle joint (15–22°) but no significant differences between methods throughout the crank cycle when assessed using Statistical Parametric Mapping were observed for any of the joints. OpenPose presented stronger agreement with marker-tracking (criterion) than the MSRA for the hip and knee joints but resulted in poor agreement for the ankle joint.

Theoretical and Practical Studies of Determining the Force of the Lifting-Lowering of the Roll Box

The lifting and lowering mechanism of the roll box of the saw gin, being an integral part of the ginning process, is used when starting the electric motor of the saw cylinder until its rated speed is reached to prevent an increase in the load current on it, as well as to start the ginning process. The article defines the kinematics of the movement, and also studies the regularity of the movement of the roll box of the saw gin when lifting it with the help of a pneumatic drive. The kinematics of the roll box movement was determined through experimental studies. Knowing the equation of motion, using the second-order Lagrange equation, the regularity of the change in the lifting force of the roll box was determined. Here the system is closed, its degree of freedom is equal to one. The angle of rotation of the roll box is taken as a generalized coordinate. Numerical results were obtained using the Matlab software environment. The theoretical analysis and graphs for determining the lifting force of the roll box are presented. To study the kinematics of lifting the roll box, a method and a test bench have been developed. According to him, when the roll box was raised, its movement was recorded on video, the image was processed using the After Effect and CorelDraw programs, and the movement of the rod attachment point to the roll box was determined. And also the equation for changing the angle of rotation of the roll box is determined using the Matlab Curve Fiting program.

Coordination of Lower Limb During Gait in Individuals With Unilateral Transfemoral Amputation.

Understanding the lower-limb coordination of individuals with unilateral transfemoral amputation (uTFA) while walking is essential to understand their gait mechanisms. Continuous relative phase (CRP) analysis provides insights into gait coordination patterns of the neuromusculoskeletal system based on movement kinematics. Fourteen individuals with uTFA and their age-matched non-disabled individuals participated in this study. Kinematic data of the lower limbs of the participants were collected during walking. The joint angles, segment angles, and CRP values of the thigh-shank and shank-foot couplings were investigated. The curves among the lower limbs of the participants were compared using a statistical parametric mapping test. Compensatory strategies were found in the lower limbs from coordination patterns. In thigh-shank coupling, although distinct coordination traits in stance and swing phases among the lower limbs were found, the lower limbs in both groups were discovered to remain in a similar coordination pattern during gait. For individuals with uTFA, in shank-foot coupling, intact limbs demonstrated a short period of foot-leading pattern which was significantly different from that of the other limbs during mid-stance to compensate for the weaker force generation by prosthetic limbs. The findings offer normative coordination patterns on the walking of individuals with uTFA, which could benefit prosthetic gait rehabilitation and development.

Neurodata Tracker: Software for computational assessment of hand motor skills based on optical motion capture in a virtual environment.

Deficits affecting hand motor skills negatively impact the quality of life of patients. The NeuroData Tracker platform has been developed for the objective and precise evaluation of hand motor deficits. We describe the design and development of the platform and analyse the technological feasibility and usability in a relevant clinical setting. A software application was developed in Unity (C#) to obtain kinematic data from hand movement tracking by a portable device with two cameras and three infrared sensors (leap motion®). Four exercises were implemented: (a) wrist flexion-extension (b) finger-grip opening-closing (c) finger spread (d) fist opening-closing. The most representative kinematic parameters were selected for each exercise. A script in Python was integrated in the platform to transform real-time kinematic data into relevant information for the clinician. The application was tested in a pilot study comparing the data provided by the tool from ten healthy subjects without any motor impairment and ten patients diagnosed with a stroke with mild to moderate hand motor deficit. The NeuroData Tracker allowed the parameterization of kinematics of hand movement and the issuance of a report with the results. The comparison of the data obtained suggests the feasibility of the tool for detecting differences between patients and healthy subjects. This new platform based on optical motion capturing provides objective measurement of hand movement allowing quantification of motor deficits. These findings require further validation of the tool in larger trials to verify its usefulness in the clinical setting.